ABC News’ Richard Esposito and Dean Schabner report:

An internal New York Police Department review has found a senior police officer violated NYPD guidelines when he used pepper spray on Occupy Wall Street protesters last month, ABC confirmed.

According to a person with knowledge of the investigation, Deputy Inspector Anthony Bologna faces discipline of a loss of 10 vacation days as a result of the incident on Sept. 24.

According to officials, after the demonstrators left their base in Zuccotti Park and spilled over into the streets, blocking traffic, Bologna approached a group already corralled by police and sprayed the group with pepper spray.

Clips on the Occupy Wall Street website show the incident, when a group of young women who were penned in by orange netting were approached by Bologna, who then without apparent warning, used pepper spray on them. Two of the women hit by the spray fell to the ground and one screamed.

Bologna has the option to appeal the decision.

“Deputy Inspector Bologna is disappointed at the results of the department investigation,” Roy Richter, president of the NYPD captain’s endowment association, said in a statement. “His actions prevented further injury and escalation of tumultuous conduct. To date, this conduct has not been portrayed in its true context.”

The Occupy Wall Street protests began in downtown New York City Sept. 17, and have continued with the occupation of a park in the city’s financial district and several large-scale marches, generally on weekends. Though many of the group’s marches have resulted in dozens of arrests, there has been very little violence and conflicts between the protesters and police have been limited.